In Dolgellau, as everywhere, each glazing bar on a roof lantern has a top capping that clamps the glass onto gaskets. Send photos and we'll tell you what we think has failed.

What you might be seeing
- Gasket rubber poking out, cracked or missing
- Water running down one glazing bar inside
- End caps missing at the bottom of a bar
What usually causes it?
Fixings working loose
Screws and clips that hold the capping relax with thermal movement, so the clamp on the glass weakens.
Damage
Ladders, window cleaning or someone stepping on a lantern can bend a capping or unclip it.
Covering Dolgellau and nearby
Wind-driven rain is the real test of a roof lantern, and the wetter west sees plenty of it. Leaks that appear only in a storm from one direction usually point to the cappings or eaves on that face — a useful clue when you send us photos.
Coastal wind drives rain hard against lanterns, so cappings and ridge seals on the seaward face take the most punishment.
We cover Dolgellau as part of Gwynedd, about 35 miles from Bangor, Gwynedd.
If you're just outside Dolgellau, we also cover Machynlleth (11 miles), Porthmadog (16 miles), Aberystwyth (24 miles).
Guide prices for glazing bar and capping repairs in Dolgellau
Guide price for glazing bar and capping repairs: £165–£395 ex VAT (£198–£474 inc VAT), per lantern. Towers or scaffold, where needed, are priced into the quote. Your fixed price is confirmed in writing before any work starts.
Do you need permission in Wales?
Straightforward repairs — resealing, gaskets, cappings, eaves and like-for-like parts — don't normally need building regulations approval in Wales. Replacing the whole lantern or enlarging the opening is different and falls under the Building Regulations 2010 (as applied in Wales); we confirm in writing which route applies before any replacement. Listed buildings in Wales need listed building consent from the local planning authority for alterations, with Cadw guidance on historic buildings; check with the council before changing a lantern on a listed property.
How does it work?
- Send photosWhatsApp or upload a few photos and tell us when it leaks.
- Guide priceWe reply with a guide price and whether a visit is needed.
- Fixed price in writingYou approve the price and the date before anything starts.
- Repair and testWe fix what's failed, water-test where it matters, and send photos.
Glazing bar and capping repairs in Dolgellau: questions
How do I get a price for glazing bar and capping repairs in Dolgellau?
Send a few photos of the lantern and the problem, with your Dolgellau postcode. We'll reply with a guide price and tell you whether a visit is needed before we can fix the price.
Which places near Dolgellau do you cover?
As well as Dolgellau, we cover nearby Machynlleth, Porthmadog, Aberystwyth, Pwllheli and the rest of Gwynedd.
How much do capping and gasket repairs cost?
Usually £165–£395 ex VAT per lantern depending on how many bars are affected, confirmed in writing before work starts.
Do you repair uPVC and timber lantern bars too?
Yes. Timber lanterns use different beads and cappings, and we repair those as part of timber lantern repairs.
Other lantern repairs in Dolgellau
- Eaves beam and gutter repairs in Dolgellau
- Misted glass unit replacement in Dolgellau
- Cracked lantern glass replacement in Dolgellau
- Flat rooflight and skylight repairs in Dolgellau
- Leak investigation and inspection in Dolgellau
- Urgent leak make-safe in Dolgellau
Glazing bar and capping repairs near Dolgellau
More about glazing bar and capping repairs · All roof lantern repairs in Dolgellau